Surface treating device



06.28, 1969 L. HANSEN SURFACE TREATING DEVICE Filed Dec. 19, 1966 2 Sheets-Sheet l Oct. 28, 1969 E. l.. HANSEN 3,474,512

SURFACE TREATING DEVICE Filed Dec 19, -1966 2 Sheets-Sheet 2 a nv VEA/ron 6, 56 6, sama/Po 1.. HANSEN ATTORNEY United States Patent O 3,474,512 SURFACE TREATENG DEVICE Edward L. Hansen, San Francisco, Calif., assigner of one-Sixth to George B. White, San Francisco, Calif. Filed Dec. 19, 1966, Ser. No. 602,700

` Int. Cl. B23d 67/00 U.S. Cl. 29-76 6 Claims ABSTRACT OF THE DISCLOSURE In -a pneumatically reciprocated surface nishing device, for instance rasping or sandpapering, a reciprocated shoe with upturned curved ends into which the ends of sandpaper are clamped by a resiliently compressible roller on a wire frame pivoted on the shoe; and a rasp support with upturned flanges slideable over the curved ends of the shoe to hold a rasp on the shoe; the shoe is slideable on guides fixed -to the housing of the device and is connected to a reciprocating U-shaped drive, which latter is yieldably mounted on piston rods extending from opposite ends of a piston working in -a cylinder; arms extending from the same piston rod alternately strike opposite valve stems to shift the valve to reverse the reciprocation of the piston; the device is controlled by a manual valve on a handle on the housing.

CROSS REFERENCE This invention is an improvement on the type of surface treating device shown in U.S. Patent No. 2,622,563 issued to Mario Pisani and Edward L. Hansen on Dec. 23, 1952.

BRIEF SUMMARY OF THE INVENTION The novel features of the present application include, the yieldable mounting of the drive carriage on the piston rod and the cushioned action betwen the valve stem and the piston rod; also the quick and easy clamping of treating sheet, such as sandpaper, over the shoe, and suitably quickly interchangeable support for a rasp or the like, all in a shaped casing compactly accommodating the working mechanisms.

I am aware that some changes may be made in the general -arrangements and combinations of the several devices and parts, as well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the following specification, and as defined in the following claims; hence I do not limit my invention to the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the foregoing and other objects in view, which will ybe made manifest in the following detailed description, reference is had to the accompanying drawings for the illustrative embodiment of the invention, wherein:

FIG. l is a longitudinal sectional View of the device.

FIG. 2 is a partly sectional view of an attachment t-o the device.

FIG. 3 is a cross-sectional view of the device, the section being taken on lines 3--3 of FIG. 1.

FIG. 4 is a fragmental partly sectional view of an end of the carriage shoe with the auxiliary shoe mounted thereon at one end thereof.

FIG. 5 is a perspective fragmental partly'sectional view of one end of the carriage shoe with the clamping roller.

FIG. 6 is a cross-sectional view taken on lines 6-6 of FIG. l.

FIG. 7 is a sectional detailed view of the carriage supice port on the end of one of the piston rods, the section being taken on lines 7-7 of FIG. 1.

In the illustrative embodiment herein the moving parts are suspended in a hollow casing 1 which has a forward end 2 and a trailing end 3. The forward end has a handle 5 on it for guiding the tool. The trailing end 3 is concave to facilitate the manipulation of the control valve 4 on a manipulating handle 6. On the inside of the top 7 of the casing 1 is mounted, by means of suitable screws 8, a double cylinder block 9. In the cylinder block 9 there are two cylinders, namely a valve cylinder 11 nearer to the top 7 and a main cylinder 12 parallel with and beneath the valve cylinder 11.

In t-he valve cylinder 11 works a multiple sliding valve 13 which is substantially the same structure as shown in said U.S. Patent No. 2,622,563. The multiple sliding valve 13 has three spaced cylindrical valve heads 14. The valve cylinder 11 has a valve intake port 16. A valve outlet port 17 is spaced from the valve intake port 16 to one side and is connected by a communicating passage 18 to an end port 19 of the main cylinder 12 near the end of the main cylinder 12 farthest from the valve outlet port 17. Another valve outlet port 21 of the main cylinder 12 is spaced from the valve intake port 16 to the opposite side and is connected by a cross passage 22 to another end port 23 at the other end of the main cylinder 12 farthest from the valve outlet port 21. The valve heads 14 are so spaced from one another that at one end of the comparatively short stroke of the sliding valve 13 the valve intake port 16 is open to the valve outlet port 17 whereby compressed air is admitted through the passage 18 and end port 19 to one side of the piston 24 working in the main cylinder 1'2. The end ports 19 and 23 function both as intake and ex-haust ports, so that when pressure is admitted through the end port 19, then air is exhausted from the other side of the piston 24 through the other end port 23 and passage 22 and valve outlet port 21. The valve Ihead 14 adjacent the valve outlet port 21 uncovers at least partially an exhaust port 26 through which the air is exhausted into an exhaust passage 27 to the outside of the block 9 within the casing 1. When the middle valve head 14 is shifted in the opposite direction so as to uncover communication between the valve intake port 16 and the other valve outlet port 21, then air under pressure is introduced through the passage 22 and the other end port 23 to the other side of the piston 24, and at the same time the valve Ahead 14 nearest to the first valve outlet port 17 uncovers another exhaust port 28 which leads into the exhaust passage 27 for exhausting the air from behind the piston 24 as heretofore described. The valve heads are `so spaced from one another as to accomplish the alternate communications between the valve into port 16 and the respective valve outlet ports 17 and 21 upon the alternate strokes of the sliding valve 13.

A piston rod 29 extends from each side of the piston 24 through the opposite closed ends 31 of the main cylinder 12. A U-shaped bracket plate 32 has forked legs 33 extended spaced from the respective closed ends 31 over the respective piston rods 29. Each piston rod has fixed thereon a collar 34. Each collar 34 has grooves or slots 36 on its opposite sides which are engaged by the adjacent forked legs 33 of the bracket plate 32. On a threaded end 38 of each piston rod 29 is secured a nut 39. The head of the nut 39 is spaced from the adjacent collar 34 by a hub 41. A valve actuating arm 42 is perforated so as to fit over the hub 41 between the adjacent collar 34 and the head of the nut 39. The valve actuating arm 42 extends so that its tip 43 is approximately in registry with the axis of the sliding valve 13. The lower end of each valve actuating arm 42 has a horizontal flange 44 which extends below the adjacent end of the U-shaped bracket plate 32 so as to limit the downward play of the bracket plate 32 on the collars 34. A cushion Washer 46 is provided between the head of the nut 39 and the actuating arm 42, and another cushion washer 47 is provided between the arm 42 and the yoke 37 so as to yieldably hold the yoke 37 in position.

The valve heads 14 are connected by valve stem portions 48 and a valve stem 49 extends from each end of the sliding valve 13 through a dash-pot 51 in each end of the valve cylinder 11. On each valve stem 49 is an abutment head S2 suitably secured as by a set screw 53. The face of the abutment head 52 facing the end of the valve cylinder 11 has a compressible cushion washer 54 thereon.

The part of the device heretofore described provides a self adjustable or floating support for the drive carriage formed by the U-shaped bracket plate 32 and also cushions the impact between the respective valve actuating arms 42 on the adjacent abutment heads 52 for the alternate strokes of the sliding valve 13 at the respective ends of the str-okes of the piston 24. This resiliently yieldable impact arrangement assures smoother operation and control of the reciprocation of the U-shaped bracket plate 32 which transmits motion to the actual surface treating mechanism. The aforedescribed structure could be used for the direct mounting of a shoe for the surface treating elements such as abrasive sheet or file of the type shown in said Patent No. 2,622,563.

In the present illustration an improved drive and shoe support is illustrated in FIG. 1. A shoe plate 56 has longitudinal side flanges 57. Bushings 58, provided with antifriction lining 59, are secured between the side flanges '57 spaced from the respective ends of the shoe plate 56 and from one another. There is a pair of transversely spaced bushings 58 near each end of the shoe plate 56. The bushings S8 ride on spaced guide rods 61. The guide rods 61 are fixedly mounted at their ends on brackets 62, which latter are bolted or otherwise secured to the respective ends of the casing 1. The shoe plate S6 is spaced below the U-shaped bracket plate 32 and it has thereon, opposite said bracket plate 32, a rack 63 the teeth 64 of which face toward the bracket plate 32. A parallel rack 66 is mounted on the U-shaped bracket plate 32 spaced from and facing the shoe plate rack 63. An idler gear 67 is journalled on a fixed cross shaft 68 in engagement with both racks 63 and 66. The cross shaft 68 is secured in suitable end brackets 69 mounted on the respective sides of the casing 1. Thus as the U-shaped bracket plate 32 is reciprocated by the reciprocation of the piston 24, the rack 66 thereon rotates the gear 67 which in turn drives the shoe plate rack 63 oppositely to the movement of the U-shaped bracket plate 32 but parallel thereto, and thereby reciprocates the shoe plate 56 and the surface treating sheet carried on the shoe plate 56.

Each end of the shoe plate 56 is turned upwardly so as to form a concave-convex flange 71. Each curved flange 71 is so formed that the convex face thereof is facing to the outside and the concave or dished portion thereof faces toward the other flange. A generally U-shaped clamp 72 has its legs 73 pivoted at 74 in the opposite side flanges 57 of the shoe plate 56 spaced from the adjacent curved flange 71. The outer portions 76 of the legs 73 are bent toward the adjacent Curved flange 71 so as to be engageable with the concave or dished side of the adjacent curved flange 71. A resiliently compressible clamp roller 77 is provided on the cross bar 78 of each clamp 72 for tight engagement with the dished inner side of the adjacent curved flange 71. The relation of the clamp 72 and the curved flange 71 is such that the roller 77 is tightly snapped into the concave or dished side of the curved flange 71. There is a similar clamp adjacent each curved flange 71. Thus if a flexible sheet, such as an abrasive sheet is used for treating the surface, it is placed on the bottom of the shoe plate 56 and the ends thereof are wrapped around the respective curved flanges 71 and then the roller 7 of the clamp 72 is snapped into the curved adjacent flange 71 thereby firmly holding the sheet in position. This provides for a very quick and easy clamping of such sheets into the machine.

The device shown in FIG. 2 is an attachment for mounting a metal file or similar rigid surface treating device on the shoe plate 56. An auxiliary shoe plate 81 fits over the underside of the shoe plate 56. Each end of the auxiliary shoe plate 81 is provided with a flange 82 which flange is curved to conform to the shape of the curved flange 71 of the shoe plate 56 and is turned upOn itself to form a lip 83 fitting into the concave or dished portion of the curved flange 71. The lip 83 is so spaced from the flange 82 that it can be slid sidewise over the respective flange 71 for quick attachment to the shoe plate 56. From the underside of the auxiliary shOe plate81 extend spaced parallel longitudinal flanges 84. Between the flanges 84 at the auxiliary shoe plate 81 nearest to the front end 2 of the casing 1 is a fixed cross plate 86 spaced from the shoe plate 81. Over the outer edge of the cross plate 86 can be clamped a hook 87 on the forward edge of a one-way rasp 88. Near the other end of the auxiliary shoe plate 81 and between the flanges 71 is a slidable support 89 which is of U-shaped cross section. The sides 91 of the slideable support 89 are in slideable contact with the insides of the parallel longitudinal flanges 84. Longitudinal slots 92 in the respective slideable support sides 91 are supported on and ride on guide pins 93 on the respective longitudinal flanges 84. A coil spring 94 has one end thereof anchored on the auxiliary shoe plate 81 and the other end thereof anchored at the forward edge of the slideable support 89 so that the spring 94 normally pulls the slideable support 89 toward the adjacent end of the auxiliary shoe plate 81. The one-way rasp 88 has another hook 96 at its trailing end. In order to mount the one-way rasp 88 tightly in place, its hook 96 is hooked on the trailing edge of the slideable support 89 and then the rasp 88 is pulled toward the other end of the auxiliary shoe plate 81 so as to slide the slideable support 89 against the tension of the coil spring 94 until the leading hook 87 thereof is hooked on the cross plate 86. Then the action of the coil spring 94 pulls the leading hook 87 into tight engagement. Being that the rasp 88 works on the stroke toward the front Or leading end 2 of the casing 1, the leading hook 87 furnishes solid backing for the rasping operation. The rasp 88 being somewhat slightly shorter than the distance between the leading edge of the cross plate 86 and the trailing edge of the slideable support 89, is held tightly, yet permits quick attachment or replacement.

The operation of the device is controlled from the manipulating handle 6 substantially in the manner described in said Patent No. 2,622,593. In the present form the manipulating handle is a curved handle of the pistol grip type, on one end 97 of which is suitably bolted 01' otherwise secured thereon an attachment plate 98 which in turn is bolted to the top 7 of the casing 1. The control valve 4 is mounted on the free end 99 of the manipulating handle 6 and it has a trigger finger 101 in con venient position to be manipulated by the operator. The control valve 4 of usual construction has a conduit 102 suitably connecting it through the top 7 of the casing 1 to the valve intake port 16. Suitable connection 103 is provided on the valve 4 for connecting it to a source of compressed air.

In operation the operator holds the forward handle 5 with one hand and the manipulating handle 6 with the other hand, with a finger on the trigger finger 101 and manipulates the trigger finger 101, whereupon the air admitted through the valve intake port 16 is transmitted to the main cylinder 2 to work the piston 24, and at the end of each piston stroke 24 the respective valve actuated arm 42 abuts against the adjacent abutment head 52 to reverse the position of the sliding valve 13 thereby to reverse the stroke of the piston 24 in the manner heretofore described. The yieldable support of the valve actuating arms 42 and the U-shaped bracket plate 32 provides for smoother operation and reciprocation of the shoe plate 56. The surface treating sheets or attachments can be quickly or easily mounted on the curved flanges 71 at the ends of the shoe plate 56 and are positively held for eicient and smooth reciprocation for the treating of surfaces.

I claim:

1. In a reciprocating surface treating device,

(a) hollow casing open at its bottom,

(b) a main cylinder mounted in said casing,

(c) a piston working in said main cylinder,

(d) valve means mounted in said casing adjacent said main cylinder and interconnected with said main cylinder for alternately admitting a pressure medium to opposite sides of said piston for reciprocating said piston in said main cylinder,

(e) means actuated by the reciprocation of said piston at the end of each stroke of said piston for reversing said valve thereby to alternate the admission of pressure medium to the respective opposite sides of said piston,

(f) piston rods extending from opposite sides of said piston to the respective ends of said main cylinder,

(g) a shoe exposed at the bottom of the casing,

(h) means to reciprocably support said shoe on said casing,

(i) means to transmit movement from said piston rods to said shoe for reciprocating said shoe,

(j) handle means on said casing,

(k) trigger controlled valve on said handle means connected to said alternating valve and connected to the pressure medium for the control of pressure medium to said alternating valve,

(l) said shoe having a pair of curved flanges extending inwardly of said casing with the concave sides of the flanges facing one another,

(m) a generally U-shaped clamp pivoted on said shoe adjacent the concave side of each curved flange and turnable into the adjacent concave side,

(n) a resiliently compressible transverse member on said clamp tightly fitting into said concave side of each ange for clamping a surface treating element onto said shoe,

(o) an auxiliary shoe attachment having opposite curved flanges at its ends,

(p) the end of each ange of said auxiliary shoe attachments being turned back toward the other flange and upon its concave side so as to slideably fit over the respective adjacent curved flange of said shoe, and

(q) means on said auxiliary shoe attachment adapted to hold a rasp on said auxiliary shoe attachment.

2. The invention defined in claim l,

(r) a rasp having a hook at each end,

(s) said rasp holding means including spaced cross elements on said auxiliary shoe attachment engageable respectively by said hooks on said rasp to hold said rasp in operating position, and

(t) means to resiliently mount one of said cross elements for holding said rasp under tension in one direction.

3. In a reciprocating surface treating device,

(a) hollow casing open at its bottom,

(b) a main cylinder mounted in said casing,

(c) a piston working in said main cylinder,

(d) valve means mounted in said casing adjacent said main cylinder and interconnected with said main cylinder for alternately admitting a pressure medium to opposite sides of said piston for reciprocating said piston in said main cylinder,

(e) means actuated by the reciprocation of said piston at the end of each stroke of said piston for reversing said valve thereby to alternate the admission of pressure medium to the respective opposite sides of said piston,

(f) piston rods extending from opposite sides of said piston to the respective ends of said main cylinder,

(g) a shoe exposed at the bottom of the casing,

(h) means to reciprocably support said shoe on said casing,

(i) means to transmit movement from said piston rods to said shoe for reciprocating said shoe,

(j) handle means on said casing,

(k) trigger controlled valve on said handle means connected to said alternating valve and connected to the pressure medium for the control of pressure medium to said alternating valve,

(l) said means to transmit movement from said piston rods to said shoe including a substantially U-shaped bracket,

(m) resiliently yieldable means to hold the legs of -said U-shaped bracket on the respective ends of said piston rods, and

(n) connecting means to transmit the movement of said U-shaped bracket to said shoe.

4. The invention dened in claim 3,

(o) said connecting means including facing racks respectively on said bracket and on said shoe, and

(p) a pinion rotatably supported in said casing in engagement with said racks.

S. The invention dened in claim 3,

(l) said means to reciprocably support said shoe including a pair of spaced longitudinal guide elements iixed in said casing,

(n1) bearing blocks on said shoe slideable on said xed guide elements.

6. The invention defined in claim 3, and

(l) said casing having a forward end and a trailing end,

said trigger controlled valve being adjacent said trailing end, and said trailing end being concave to accommodate the hand of the operator for manipuv lating the trigger of said trigger controlled valve, and

(m) a handle on the forward end of said casing for guiding said device.

References Cited UNITED STATES PATENTS 2,334,172 ll/l943 Champayne 51-170 2,614,369 l0/l952 Robins 5l--l70 2,622,563 12/1952 Pisani et al. 51--170 XR 3,214,823 11/1965 Hendrickson 29--76 HARRISON L. HINSON, Primary Examiner U.S. Cl. X.R. 

